Rotary underreamer



July 26, 1938.

F. wlNTEMU'rE 2,124,663

ROTARY UNDERREAMER Filed Aug. 2, 1957 40 IN V EN TOR.

@m WMM@ Patented July 26, 1938 UNITED STATES PATENT OFFICE 11 Claimx.

My invention relates to improvements in rotary underreamers in which pivotally mounted cutters operate in conjunction with a reamer body for the purpose of enlarging the diameter of a well.

The objects of my improvements are, rst. to provide an underreamer with more simple and eillcient means for retracting and extending the cutters; second, to provide an underreamer with operating means whereby the length of cutters that can be retracted within the periphery of a correspondingly lengthy body is unlimited; third, to afford facilities whereby the cutters can be changed whilst the underreamer is connected to the drill collar or pipe, other objects and advantages will be apparent as the invention is better understood from the following description when considered in connection with the accompanying drawing illustrating a preferred embodiment thereof.

On the drawing,

Figure 1 is a sectional elevation of the underreamer showing the cutters in extended position.

Fig. 2 is a sectional elevation, showing the cutf ters in retracted position.

Fig. 3 is an elevational outside view of the underreamer showing the slot arrangement with the cutters in extended position.

Fig. 4 is a sectional view taken from the line 4 4 Fig. 1.

Fig. 5 is a sectional view taken from the line 5 5 Fig. 2.

Similar numerals refer to similar parts throughout the several views.

Referring more particularly to Figs. l and 2, the numeral III indicates the body of the underreamer. The body has a threaded 'pin connecting joint l2 at the upper end, and cylindrical bore I4 forming a central passage way through the upper portion for the conveyance of hydraulic fluid and for the accommodation of an extension spring I6 which is suspended at its upper end from a removable cross piece I8. I'his cross piece is supported in a groove at the top of the pin joint. 'I'he lower end of the spring is connected to and supports the hydraulic piston 2|! also located in the central bore I4. The piston has a-central passage way 22 for the passage of the ushing out fluid, it also allows the fluid to pass in and out of the drill pipe as the tool is being lowered into or is being withdrawn from the well.

Below the piston is the yoke 24 which is attached to the piston by the bolts 26. The socket 2l is threadedly connected at its upper end to the (Cl. Z-76) yoke 24, the lower end being slotted and welded to the end of the plate member 3l, thus rigidly connecting the plate to the piston. 'I'he plate 30 extends downwardly between the cutters 32 and 34 and the centrally located elongated opening 36 allows the plate to straddle the pivotal bolt 3B and act as a guide to keep the plate in central position. 'I'he bolt Il passes transversely through the body l0, through both cutters and the plate and thus pivotally supports the cutters. The pins 40 and 42 located in the lower rear portion of each cutter extend into the slots 4I and 43 in each edge of the plate 30 and in which they slide inwardly and outwardly as the cutters turn and the plate reciprocates. The part of the plate containing the slots extends outwardly far enough to prevent the pins 4I from sliding out of the slots even when the pins are in their outermost position. 'I'he upward movement ofthe plate is limited by the bottom of the opening 36 striking against the bolt 3l, and the upward movement of the cutting end of the cutters is limited by the cutters coming in contact with the top of the slot 44 which is formed transversely through thelower portion of the body Il, the slot 44 being of suillcient length and width to accommodate the cutters and plate when in retracted or extended position. The cutters are sustained in retracted position by the pull of the extension spring I6 operating on the pins 4I and 42 to which it is connected by the plate $0, the socket 28, the yoke 24, the bolts 26 and the piston 20, this causes the cutters to turn on the stationary pivotal bolt 38 until the cutters are in an upright position and within the periphery of the body. In order to change the cutters from retracted to extended position. hydraulic fluid is forced down the drill pipe into the bore I4 where it extends the spring by forcing down the piston, this forces down the plate 3l which causes the cutters to turn on the pivotal bolt 28 until they come into contact with the top of the slot 44, the cutters are then in fully extended position. 'I'he fluid 'then passes on under pressure through the passage 22 in the piston into the chamber 25 and out along the outer edge of the plate 30 between the cutters where it carries away the cuttings.

The stepped notches 46 and 48 on the edge of the plate 20 are for the purpose oi' inserting hand levers through the narrow slots l0 located opposite theedges of the plate Il so that the plate may be forced down to the extra space 52 in the plate opening 3l. shown in Fig. 1, this relieves the pressure of the cutters on the bolt 38, the bolt may then be removed enabling the cutters to be pulled out and replaced whilst the underreamer is attached to the drill collar or pipe.

The pilot bit or blade M is secured in the base of the body lil by being welded into the slot I8.

I am aware that prior to my invention rotary underreamers have been made with pivotally mounted cutters operating in conjunction with a reamer body, I therefore do not claim such a combination broadly, but

I claim:

1. A rotary underreamer embodying a body, a cylindrical hydraulic uid conveying bore centrally located in the upper portion of the body, a spring in the bore, a hydraulic piston supported by the spring, a plate member secured to the piston, a pivotally mounted extensible cutter on each side of said plate, a pin attached to each cutter and extending into the plate whereby the cutters are moved into extended or retracted position by the action of the hydraulic piston or the spring.

2. A rotary underreamer embodying a body, a cylindrical hydraulic fluid conveying bore oentrally located in the upper portion of the body, a spring in the bore, a hydraulic piston supported by the spring, a plate member secured to the piston, extensible cutters mounted upon a stationary pivot extending into the body, said plate having a transverse slot in the edge on each side thereof for the accommodation of a pin extending outwardly from the lower rear end of each cutter, each pin being slidably positioned in the opposite slot so that the cutters may be extended or retracted bythe plate as the plate is actuated by the hydraulic piston or the spring.

3. A rotary underreamer embodying a body, a cylindrical hydraulic iluid conveying bore centrally located in the upper portion of the body, a spring in said bore, a hydraulic piston supported by said spring, a plate member supported by said piston, said plate being slidably positioned between a pair of cutters mounted upon a pivot passing transversely through the body, said plate having a centrally located elongated opening through which the pivot passes and a transverse slot in the edge on each side of the plate for the accommodation of a pin extending outwardly from each cutter and extending into the opposite transverse slot whereby the cutters are turned upon the pivot by the action of the spring or the hydraulic piston.

4. A rotary underreamer embodying a body, a cylindrical fluid conveying bore centrally located in the upper portion of the body, an extension spring supported at its upper end by a cross piece resting in the body, a hydraulic piston suspended from the lower end of the spring, a downwardly extending plate member rigidly supported by said piston slidably positioned between a pair of cut. ters located in a transverse slot passing through the bodyl said cutters being mounted upon a pivot supported by the body at both ends, said pivot passing through the cutters and plate, a pin in the lower rear end of each cutter extending into a transverse slot in the outer edge of the plate, an elongated centrally located opening through the plate allowing the plate to reciprocate about the stationary pivot as the piston moves upwardly by the pull of the spring or downwardly by the force of the flushing out iiuid acting upon the piston.

5. A rotary underreamer embodying a body, a cylindrical fluid conveying bore passing centrally through the upper portion of the body, a piston having a fluid passage therethrough located in said bore, a downwardly extending plate member threadedly attached to said piston, said plate member having an elongated central opening through which a body supported pivot passes, a cutter on each side of said plate member slidably positioned in an opening through said body, said cutters being pivotally supported by said pivot, a pin in the lower rear end of each cutter, a slot through the edge on each side of said plate, each slot being in alignment with a pin and into which the pin extends, so that as the piston reciprocates the cutters turn upon the pivot into extended or retracted position.

6. A rotary underreamer embodying a body, a pivotal member extending through said body. a slot formed transversely to the pivotal member through said body, a pair of extensible cutters in said slot and mounted upon said pivotal member, a reciprocal plate member between said cutters, a pin slidably connecting the lower rear end of each cutter to a slot through each edge of said plate member, the upper end of said plate member being connected to a piston located in the upper portion of said body, so that as the cutters retract from extended position the piston is forced upwardly.

7. A rotary-*underreamer embodying a body, a pair of extensible cutters slidably positioned in a transverse slot formed through said body, said cutters being mounted upon a pivot, a plate member slidably located between and being connected to both cutters, said plate being also in connection with the actuating means whereby the cutters are extended and retracted in turning upon the pivot, stepped notches on the edge of said plate for the accommodation of hand leyers used for the purpose of adjusting the cutters so that the cutters may be removed or inserted whilst the tool is in connection with the drill Pipe.

8. A rotary underreamer embodying a body, a pair of extensible cutters slidably positioned in a transverse slot formed through said body, said cutters being mounted upon a pivot, a plate member slidably located between and being connected to both cutters, said plate being also in connection with a spring and a hydraulic piston whereby said cutters are forced to turn upon the pivot, a pilot blade welded into a slot in the base of said body, a fluid passage through the upperportion of the body for conducting fluid from the top of the tool into the transverse slot in which the cutters are mounted.

9. A rotary underreamer embodying a body, a hydraulic tluid conveying bore through the upper portion of the body, a hydraulic piston member located in said bore, a plate member secured to the piston member, a pivot supported by said body, extensible cutters pivotally mounted upon said pivot, the plate member having a transverse slot in the edge on each side thereof, each slot being provided for the accommodation of a pin extending outwardly from the lower rear end of each cutter, the pins being slidably positioned in the slots so that the cutters are forced to turn upon the pivot as the piston member reciprocates.

l0. A rotary underreamer embodying a body, a hydraulic fluid conveying bore through the upper portion of the body, a piston member located in said bore, a plate member secured to said piston member, a pivotally mounted extensible cutter on each side of said plate member, a slidable connecting piece positioned in each edge of said plate member and slidable therein, each connecting piece extending into the rear end of a cutter thus connecting the rear end of each cutter with the plate member whereby the cutters are caused to turn upon the pivot as the piston member reciprocates.

1l. A rotary underreamer embodying a b ody, a hydraulic iluid conveying bore through the upper portion oi the body, a hydraulic piston member in said bore, a plate member in connection with and operated by said piston member, said plate member being slidably positioned between a pair of cutters located in an opening through said body and mounted upon a pivot supported by said body, said plate member having a centrally located elongated opening through which the pivot passes and a transverse slot in the edge on each side oi' the plate member'for the accommodation of a pin extending outwardly from the rear end of each cutter and extending into the opposite transverse slot whereby the cutters are turned upon the pivot as the piston reciprocates.

FRANKWIN'I'EMUTE. 

